1. Field of Invention
This invention relates to the field of electric lamp and discharge devices and more specifically to linear accelerators (linacs).
2. Description of Related Art
Linear accelerator devices use intense radio frequency electromagnetic fields to accelerate the speed of particles to create beams used for a variety of applications. These applications include driving industrial processes, security & imaging applications, food and medical sterilization, medical treatments, isotope creation and physics research. Superconducting radio frequency (SRF) technology allows the construction of linear accelerators that are both compact and efficient at using “wall plug” electrical power to create a particle beam. The cavity of an SRF linear accelerator must operate at an extremely low temperature. Excitation with the radio frequency power required for particle acceleration requires constant removal of waste heat generated in the SRF cavity.
Currently, cooling SRF cavities uses large quantities of cryogens such as liquid helium. These cryogens are pressurized fluids having an extremely low temperature. To provide the needed cryogens, the cryogenic systems themselves require complex integration of expansion engines or turbines, heat exchangers, cryogen storage units, gaseous inventory systems, compressors, piping, purification systems, control systems, and safety relief and venting systems. These systems require substantial space, energy, labor and money for operation and maintenance. Use of cryogens also requires cavity tuners to compensate for radio frequency resonance changes in SRF cavities due to pressure changes. Presently these issues limit the utility of SRF linear accelerators.
There is an unmet need for more efficient and less complex cooling systems for SRF based linear accelerators.